Hydrogen storing alloys used in nickel-hydrogen batteries, etc., are substances providing great effects on the properties of the batteries, such as the discharge capacity and durability. Therefore, various crystalline phases and compositions of hydrogen storing alloys have been studied. In the past, AB5-based hydrogen storing alloys mainly composed of a rare earth element and Ni have been put into practical use. In recent years, for the purpose of high discharge capacity of batteries, the hydrogen storing alloys, which allow alloys comprising a rare earth element and Ni to contain Mg, etc., are being studied. For example, as such hydrogen storing alloys, the hydrogen storing alloys, etc., have been proposed, wherein the intensity ratio of the maximal peak intensity present in a range of 2θ=31°-33° to the maximal peak intensity present in a range of 2θ=40°-44° is 0.1 or more in an X-ray diffraction measurement using a Cu—Kα ray as an X-ray source and the molar ratio of Mg to the total amount of the rare earth element and Mg is 0.3 or more (Patent Literature 1).
However, compared to the existing AB5-based hydrogen storing alloys mainly composed of a rare earth element and Ni, the hydrogen storing alloys described above have a problem that the alloy particles are amenable to be micronized due to charge-discharge cycles. If the alloy particles are micronized, the surface area of particles increases which thereby accelerates the corrosion of alloys, and the cycle life of batteries is reduced. That is, in the batteries using the hydrogen storing alloys described above, a problem of significantly shorter cycle life occurs.